1. Field of the Invention
This invention relates to a removable insert for locating a pulling iron or anchor and creating a recess therefor in a concrete structure.
2. Description of the Prior Art
In order to be able to move cast concrete structures such as slabs, boxes, covers, or the like, it is desirable to have a number of lifting points to which a hook and cable from a lifting apparatus such as a crane or hoist can be attached.
It is desirable to have the lifting points as unobstructive as possible and preferably below the structures's surfaces. Various solutions have been proposed to provide recesses for hook attachment such as shown in the U.S. Pat. Nos. to Morley 1,045,587; Cummings 1,244,034; Forni 2,344,206; Dickson 3,298,148; Holt et al 4,386,486; Kelly et al 4,580,378; Courtois et al 4,726,562; Fricker 4,821,994; Domizio 5,004,208; and Kelly et al. 5,226,265 but none of these proposed structures is wholly satisfactory.
The U.S. Pat. No. to Domizio 5,004,208, discloses a removable recess forming insert which is intended to be immersed in wet concrete after pouring, and which carries a stirrup which is intended to be left in the recess after the concrete hardens and the insert is removed. This insert is only suitable for use where its mold thumb protrudes from the concrete and can be accessed by hand, but is not suitable for attachment to a plate which forms part of the mold for a concrete structure. It is also difficult to remove the Domizio insert due to its configuration and its service life is limited due to the wear on the stirrup release slot by the pulling therethrough of the abrasive stirrup.
The insert of the invention does not suffer from the prior art problems and provides many positive advantages.